A simplest way of automatically scheduling the processing of semi-finished products is to assign the semi-finished products one by one to a processing device which completes processing fastest. However, when a batch processing device which can collectively (i.e., at one time) process a plurality of semi-finished products is used as such a processing device, it is necessary to consider collectively a plurality of the semi-finished products to be assigned to the device in order to achieve scheduling with sufficient production efficiency.
When plenty of semi-finished products are ready, high production efficiency is achieved by constantly applying the maximum processible number of semi-finished products to the batch processing device.
However, when the semi-finished products are arriving at a sufficiently slow pace as compared with their processing time in the processing device for the reason that production of the semi-finished product takes time, better production efficiency is achieved in some cases by starting the processing before the maximum number of semi-finished products processible by the batch processing device is ready.
Conventionally, how many semi-finished products are collectively applied to the batch processing device has been determined by person's experience and intuition. However, it takes much time for preparing a production schedule and it is also difficult to work out a schedule with sufficient production efficiently.